Hunting for Australia's rich natural resources

IT'S a grey winter's day on Sydney Harbour. Ferry passengers making their way from beachside suburbs to the city are shivering in overcoats and scarves, but for Phil Schmidt of CSIRO, Australia's national research organisation, the weather is perfect. "It's not windy. That was the main thing we were concerned about," he says.

Schmidt is standing on a research vessel rolling against the swell between the North and South Head - the two outcrops of land that form the entrance to the harbour. The mild winds mean that it's safe to winch his prototype 20 metres down to the seabed. This simple yellow box of sensors, called OceanMag, could soon be helping companies discover vast new reserves of oil and gas in shallow waters (see Graphic).

Most of Australia's remaining hydrocarbon deposits are thought to be in seas less than 500 metres deep, but these regions are more difficult to explore than might be expected. One method that geologists rely on to find oil is to bounce electromagnetic pulses off the rock layers under the seabed. This helps them distinguish between deep reservoirs that contain useless saltwater and those packed with oil, but the technique often fails in shallow seas because waves and currents can disrupt the signal. Schmidt's prototype is unique because it can filter out this unwanted noise.

OceanMag is just one of a host of new Australian technologies offering smarter ways to identify places to dig or drill. The research is being driven by a resources boom in the country, which is making millionaires by the day. As a rough rule of thumb: if you can burn it or build with it, Australia is rich in it. The land is packed with coal, iron, uranium, natural gas and other geological goodies that countries such as China and India are only too keen to get their hands on (see "Boom by numbers").

Unsurprisingly, companies have been seeking to turn these raw materials into record profits. And for geologists, engineers and other specialists in the sector, pay and career opportunities have never been so good. A serious skills shortage has even triggered calls for changes to immigration law to make it easier to bring in workers from overseas to fill the gap (see "Times of plenty").

In the long term, Australia's resources boom cannot be sustained with known deposits. "Right now the mining industry is living off new discoveries near existing operations," says Brent McInnes, who heads CSIRO Mining and Exploration's discovery technology team, which was set up in 2004. "The problem is that there are real deficits in commodities such as nickel, zinc and copper, and these need to be replaced with new greenfield mines."

To achieve this, companies and researchers are focusing on three areas: improving their understanding of how ore bodies and petroleum deposits are formed; refining the techniques they use to seek out hidden ores and oil; and gaining the expertise needed to exploit far-flung and inaccessible regions.

To better understand how a region of rock forms and deforms through time, McInnes's discovery technology team has developed Alphacron, a technology that charts temperature changes in any given rock formation over millions of years. This gives clues to the likely size and location of an ore body. Minerals such as copper, or rocks that bear diamonds, such as kimberlite, are often associated with magma plumes. Alphacron can tell geologists when magmas intruded near to the rock formation, even if there is no other evidence of intrusion. It can also tell whether these magmas came from deep in the Earth or from closer to the crust.

The technology itself is simple: it works by blasting mineral samples with a laser and then analysing the gas that is given off. Apatite and zircon contain helium when they form, but over geological time they release the gas if subjected to higher temperatures. A low level of helium suggests that a magma body intruded nearby during a rock formation's history. The researchers have sold prototypes of Alphacron to research groups in China and the US.

Refining and defining

Meanwhile, companies are refining the techniques they use to seek out hidden ores and oil. Exploration geologists have long used fluctuations in Earth's gravitational field to see beneath the subsurface. Placing ground sensors across a region enables them to spot buried deposits of minerals, which show up as specific gravity anomalies (see Graphic). Melbourne resources company BHP Billiton has developed technology that can detect these anomalies from a single device on board a plane, which means it can search for mineral and hydrocarbons deposits across large and often inaccessible regions. The technology, Falcon, is already showing its potential. It has been used to identify iron formations and diamond pipes in Western Australia, and in South Africa it has identified 21 sites for future diamond exploration. In order to continue the resources boom once known deposits have been exploited, the mining industry needs to move on to far-flung and inaccessible regions.

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